The present invention relates generally to kilns, furnaces and the like and more particularly to a bottom loading kiln and the door arrangement for closing such opening. A typical kiln or furnace having a front load opening is shown in U.S. Pat. No. 2,483,968. This patent shows the kiln door operated by a parallel motion linkage which keeps the door vertically oriented as it is swung between an open and closed position.
The present invention is an improvement over this general construction wherein the opening for loading the article to be fired is moved from the front of the furnace to the bottom. With this arrangement the door itself becomes a movable hearth on which the articles to be fired are supported both in and out of the furnace. The advantages of such construction are threefold. First, the articles to be fired are brought to a point where they are easily accessible for loading and unloading the furnace, or for observing intermediate results during the actual firing. Secondly, heat leakage due to convection past the door seal is minimized and third, any load may be pre-heated by only partly closing the door-hearth plate, so that the goods are only partly supported in the firing chamber.